PALISADE TECHNIQUE AS AN EFFECTIVE METHOD OF ENDOSCOPIC SUBMUCOSAL DISSECTION FOR COLORECTAL TUMORS GREATER THAN HALF A LUMINAL CIRCUMFERENCE

Aims Although ESD has become the effective therapeutic strategy for colorectal tumors, it still remains challenging to treat large tumors, especially those greater than 50 mm in size, the size that has been reported as an independent risk factor for post-ESD complications. We invented a new technique of ESD called palisade technique, which is effective in dissecting large colorectal tumors. In this study, we investigated the outcomes of colorectal ESD using palisade technique.

Methods We retrospectively collected data of colorectal ESD using palisade technique from August 2017 until November 2018. Dual knife was used in all colorectal ESD cases. All ESDs were planned according to Japanese guideline for ESD and EMR of colorectal cancer.

Palisade technique Sodium hyaluronate solution mixed with indigo carmine was injected to lift the tumor. Using dual knife, straight submucosal tunnel was made from anal to the oral side. Multiple straight tunnels are created parallelly, leaving pillars of submucosal tissues between the tunnels resembling a palisade, which are left for the purpose of “holding” the scope for stabilization during dissection. Circumferential incision was made after the entire tumor is undermined by the tunnels then submucosal palisade was dissected one by one for tumor removal.

Results 10 patients with 10 lesions were included in the study, five in rectum, and five in colon. All tumors extended for at least over half a luminal circumference. The average tumor width was 95.9 mm, the average dissection time was 152.3 minutes, and the average dissection speed was 33.5 mm²/min. There was 100% en bloc resection rate, and 80% R0 resection rate with no perforation. There was one case of post-ESD bleeding needing endoscopic hemostasis.

Conclusions Our results have shown high R0 resection rate without serious adverse events. Palisade technique of colorectal ESD is a safe and effective method even for lesions extending over half a luminal circumference.